Some shower heads have a single spray plate in which there are a series of apertures. When the water supply in turned on, water is delivered to the spray plate is a steady, continuous stream. This is a single mode shower head and the type of spray is referred to herein as a regular spray.
Shower heads with more than one mode are known. Such modes include a regular spray and pulsed spray. The user selects the mode required by moving one part of the shower head relative to the rest of the shower head. One example of such a shower head is disclosed in U.S. Pat. No. 4,754,928. The shower head disclosed in this specification has four spray modes which includes a variable pulsating misting spray. The user selects the type of spray by rotating the bottom section of the shower head.
The misting effect in U.S. Pat. No. 4,754,928 is achieved by using a water path which expands in diameter during its passage through the shower head. The increase in diameter causes the liquid to atomise and so produces a mist. Similarly, U.S. Pat. No. 4,657,185 discloses a mist spray caused by a pressure drop due to a divergent frustoconical shape in the walls of the spray nozzle.
One effect of a mist spray is the creation of steam and so, in effect, produce a sauna in the shower stall. The effect is enhanced by using very hot water. The user then runs the risk of scalding himself/herself by selecting a different shower mode immediately after using the mist spray with very hot water.
U.S. Pat. No. 4,084,271 describes a shower attachment which enables a user to produce a sauna within a shower cubicle. The device in that patent produces steam by directing the hot water through a dedicated hose attached to the water supply behind the shower head and spraying it through a nozzle against the wall of the shower cubicle. The water supply is diverted from the normal shower head to the steam nozzle and back again by the user operating a dual ended plunger. Although, the specification refers to the possibility of scalding, it is merely in relation to the effect of the steam.
GB 2,066,704 discloses a device which produces steam through an aperture in the side of the shower head by directing hot water at a deflector shaped so that it atomises the liquid and sprays the droplets into the shower cubicle. A user switches between mist mode and other shower modes by sliding part of the shower head with respect to the water input. The design of the mist producing element is such that in order for the user to return to one of the other shower modes he must overcome the pressure of water acting on the deflector. Although, the patent discloses that the force of water makes such adjustment "extremely difficult", such adjustment is not completely impossible. Further, in the device disclosed in this patent, the mist producing part is fixed to the wall, even if used in connection with a shower head which is detachable.